Mohamed Farah of Great Britain, left, celebrates winning the gold medal in the 10,000 meters with Galen Rupp of the United States at the Olympic Stadium on August 4, 2012 in London, England.

LONDON — On an electrifying evening in the Olympic Stadium, Galen Rupp became the first U.S. man to win a medal in the 10,000 meters since Billy Mills won at Tokyo in 1964. Rupp claimed silver, finishing right behind his training partner, Mo Farah of Great Britain.

Farah gave the home team its third gold medal of the evening.

“I’m thrilled for Mo. It’s unreal,” Rupp said. “Two training partners coming in first and second. I couldn’t be happier. I wouldn’t be where I am today without him. I’m the lucky one — I get to train with the best middle distance runner in the world.”

Farah finished a thrilling race with multiple lead changes in 27 minutes, 30.42 seconds, Rupp in 27:30.9. Both train in Portland, Ore., and are coached by former marathon great Alberto Salazar.

From left, teammates Jeneba Tarmoh and Allyson Felix look toward the scoreboard to determine who among them finished third and fourth during the women's 100-meter dash at the U.S. Olympic Track and Field Trials at the University of Oregon's Hayward Field in Eugene, Ore., on Saturday, June 23, 2012. Tarmoh, who was initially called third, was eventually found to have tied Felix in 11.068 seconds.

EUGENE, Ore. — In a hastily called press conference Sunday evening, USA Track and Field officials addressed the question hanging over the Olympic Track and Field Trials here at Hayward Field: How would a tie be broken for the third and final spot in the women’s 100-meter dash?

Well, quite simply, it could come down to a simple coin toss — or a run-off, depending on what the athletes choose. Either way, the Olympic team for London will be determined by the meet’s conclusion next Sunday, USATF spokeswoman Jill Geer said. A run-off, if chosen, would likely take place at Hayward.

On Saturday, Jeneba Tarmoh and Allyson Felix each ran 100 meters in 11.068 seconds — a literal tie for third place — an outcome track and field’s governing body had never considered (so no rule was on the books). The scoreboard originally showed Tarmoh ahead of Felix, but when race officials reexamined the photos from the finish line, they determined when measuring from both athletes’ torsos that they were in a dead heat.